Ch. 20 Sustainable Energy

1. Matt Shiller Mike Tarantino Ch. 20 Sustainable Energy

2. Case Study: Sea Power • The US had plans to start build one off the coast of Cape Cod, MA. This project has been stalled for several years now due to people concerned over property value decreasing as well as marine life and the fishing industry. http://i.telegraph.co.uk/multimedia/archive/01209/WindFarm_1209799c.jpg

3. Conservation • Most of the energy we consume is wasted in the form of heat. • Not necessarily because of us, but mostly because of the technology we use. • Several European nations have higher standards of living, yet use 30-50 percent less heat then us.

4. Conservation - lighting • One technology that is wasting energy is our ways of lighting • Florescent light bulbs produce 4 times as much light at the same wattage and last 10 times longer than incandescent bulbs • Light Emitting Diodes (LED’s) consume 90% less energy, and last a lot longer than ordinary bulbs.

5. Conservation - Insulation • Energy losses can be reduced by ½ to ¾ through better insulation • Double or triple glazing windows • Thermally efficient window coverings • Sealing cracks and loose joints • Cheapest way of saving energy.

6. Conservation - Appliances • From 2001 to 2007, washing machines will use 35% less water. This will cut water use by 10.5 trillion gallons (40 trillion liters) per year. Also saves about 4 times as much electricity per year as is used to light homes. This adds $240 to the price, but will back in about 7 years. • Air conditioners since 2001 have been required to be about 20% more efficient.

7. Conservation – Natural insulation • Sod roofing. Good insulation and protection from weather. • Straw bales are good for insulation and is cheap and easy to replace. However not as waterproof.

8. Conservation – Turn Off Stuff • Unplug your devices when your not using them. Even if they are off they are still drawing power • TV • Cable Box • Video Gaming console • Printer • Chargers • By doing this the average American saved 25 percent on their monthly electrical bill. • Energy Efficiency – a measure of energy produced compared to energy consumed.

9. Conservation - Transportation • Cars and light trucks account for 40% of the US oil consumption. • The US E.P.A. says that raising the MPG of every auto by 3 would save Americans as a whole $25 billion. As well as reduce CO2 emissions by 140 million metric tons per year. • Most people in the US now drive even to places that are less than 2 km away. • The average MPG of the cars on the road in the US dropped 20.4 MPG in 2004 from 25.9 MPG in 1988. • Mostly due to the increased usage of SUV’s.

10. Solutions Conservation – Transportation • Walking • High efficiency mini cars • Smart Cars • Hybrids • Diesels • Hydrogen fuel cell autos • Net Energy Yield – total useful energy produced during lifetime of system – energy required to make useful energy available. Expressed as ratio between output and energy costs for all parts of system. • Yield to cost ratio

11. Conservation – Negawatt Programs • Alternative to creating new power plants. • “nega-”watt – demand avoidance program to save money.

12. Conservation - Cogeneration • Cogeneration – the simultaneous production of both electricity and steam or hot water in the same plant. • Produces 2 useful sources of energy • Increases net energy yield from 30%-35% to 80%-90% • Small generators, in small neighborhoods, the size of about a small house are now using biomass as fuel.

13. Solar Energy • Passive heat absorption – uses natural materials or absorptive structures with no moving parts to simply gather and hold heat. • Greenhouse

14. Solar Energy • Active solar systems – pump a heat absorbing, fluid medium like air, water or an anti-freeze solution through a relatively small collector, rather than passively collecting heat in a stationary medium like a masonry.

15. High Temperature Solar Energy • By having mirrors make light point towards a more concentrated point, that would be centralized around a tube. • The fluid inside that tube then heats up. • Also could use solar cooker.

16. Gov’t incentives • Energy policies in some states encourage conservation and alternative energy sources. • Distributional surcharges (small kWh charge levied on all utility customers to help renewable energy finance) • Renewable portfolio ( standards to require power suppliers to obtain a minimum percentage of their energy from sustainable sources). • Green pricing – allows utilities to profit from conservation programs and charge premium prices for energy from renewable sources.

17. Photovoltaic cells • Photovoltaic cells – capture solar energy and convert it directly to electrical current by separating electrons from their parent atoms and accelerating them across a one-way electrostatic barrier formed by the junction between 2 different types of semiconductor material.

18. Storage • It is difficult to store electricity. • Acid from batteries is corrosive and can damage the battery. • Batteries are also expensive. • Temperature also effects batteries. • Flywheels are current experiments for storage of energy.

19. Fuel Cells • Fuel Cells – devices that use ongoing electrochemical reactions to produce an electric current. • Adds more fuel for the chemical reaction.

20. Case Study: Sea Power • Wind energy is currently the fastest growing source of energy in the world. • British and Swedish Government have both harnessed this source of power in there portfolio of conservation of energy. • The offshore wind projects off of the UK produce as much electricity as 6 nuclear power plants. These windmills average a height of 417 feet. (statue of liberty is 111 feet tall). Saidaonline.com

21. Electrolytes that can be used in Fuel Cells • Proton Exchange Membrane: Organic Polymer containing sulfuric acid allows Hydrogen Movement but blocks Electron and oxygen • Phosphoric acid immobilized in a porous ceramic matrix as an electrolyte

22. Energy From Biomass • Wood, Wood Chips, bark, branches, leaves, starchy roots • Wood burning not used as much as used to, can produce carbon monoxide • Catalytic Combustors burn harmful hydrocarbons and CO

23. Short Supply of Wood • Fire would in very short supply in developing countries • Resorting to deforestation • 40% of world relies on fuel wood to heat homes and produce energy

24. Dung and Methane as Fuel • Burning Dung is ineffective (90% of potential heat is lost) • Harvest methane from dung (6 mill. Households in China use biogas) • Swamps are methane digesters, anaerobic Bacteria produce methane from waste

25. Fuel from Crop Plants • Ethanol (grain alcohol), methanol (wood alcohol) • Crop residue can also be use (stalks, cobs, wheat straw) • Some plants produce hydrocarbons which can be burned directly (sunflower oil)

26. Energy from Earth’s Forces • Water energy accounts for 20% of total energy • Dams use water turbines • Three Gorges Dam predicted to produce power equal to 25 nuclear power plants • Many problems with dams, floods, disruption of ecosystems, degrading water quality • Schistosomiasis caused by parasitic flatworms can be transferred to humans by snails that live in weedy waters behind dams

27. Dam Alternatives • Low-head hydropower: extract energy from small head water dams • Run-of-the-river flow: non obstructing can produce energy off of slow moving streams • Micro-Hydro Generators: same as above but smaller

28. Wind Energy • Large wind turbines can produce energy for 5000 average American Households • 3 cents/kWh • Germany world leader in wind power, then Spain then U.S • Relatively cheap and much land available in Great Plains • Create many jobs

29. Geothermal Energy • Heat within the Earth can be used, produces steam such as geysers and hot springs • California's Geysers project, 200 steam wells, produce 1,300 MW of power • Long life span, relatively no waste, no transport of fuels • Earth loops underground (constant temp. of 10-20 degrees Celsius)

30. Tidal and Wave Energy • Works like dam, turbines spin as tide flows through • Tides do not coincide with peak energy use • Drawbacks include heavy siltation, flooding of aquifers, disruption of ecosystems • Waves could amount to 16% of worlds energy

31. Ocean Thermal Electric Conversion • OTEC, warm upper level boils ammonia or Freon, spins turbines, lower level then condenses • Needed temp. difference of 20 degrees Celsius